This invention relates to apparatus for carrying a binary digital signal, having first and second logic levels between relatively rotatable first and second units through wiping electrical connecting means, such as a slip ring device for example.
Wiping joints, such as slip rings, are prone to very brief but significant interruptions of contact, and such interruptions would normally modify a digital waveform transmitted through them by introducing extra "ones" or "zeros". The modification would render the data incorrect without any immediate indication that interruption and occurred and that the data was in fact incorrect.